협주곡, or "concerto," is a musical composition typically written for a solo instrument accompanied by an orchestra. It often features three movements: fast, slow, and fast, showcasing the virtuosity of the soloist while allowing for interaction with the orchestral ensemble. The most common solo instruments in 협주곡 include the piano, violin, and cello. Famous composers like Johann Sebastian Bach, Wolfgang Amadeus Mozart, and Ludwig van Beethoven have contributed significantly to the concerto repertoire, creating works that remain popular in classical music today.